1. Field of the Invention
The present invention relates generally to containers for holding liquid or dry materials, and which are provided with an opening for removal of the material. More specifically, it relates to a bag, in particular a stand-up bag, provided with a frangible piercing point where an extraction device, such as a drinking straw, can be inserted into the container for effecting removal of the contents.
2. Description of the Prior Art
In addition to bottles and tin cans, certain types of flexible containers, especially stand-up bags which can be filled with liquid, pasty or dry goods, have recently gained acceptance. Such a stand-up bag is described, for example, in German Pat. No. 1,281,140. As opposed to tearing such bags open, cutting off their upper seal or one corner thereof, some of them are designed so that an extraction device, for example a drinking straw, can be pushed through the side wall thereof, the extraction device then being used to remove the contents of the bag.
However, since these bags usually consist of laminates, especially laminates including metal foils, e.g., aluminum, the insertion of the straw often presents difficulties, because the straws are relatively thin and tend to break or fold, and thus can no longer be used. On the other hand, if a drinking straw is pushed into the bag too hard, it may happen that both walls of the bag will be pierced, and that the contents will then leak out.
Bags of this type have been proposed that have an opening closed by a piece of an adhesive tape, or by a sealing strip on the outside wall of the bag. However, there are disadvantages associated with this manner of closing the opening, particularly if the bag is constructed of laminates. The contents of the bag in such an arrangement are in permanent contact with the different layers of the laminate, which may be foil, at the opening where the bag is to be pierced. Thus, the adhesive binding the layers of the laminate can be attacked by the contents, or, in the case of composite foils having metal layers, these are affected. This may lead to delamination and thus destruction of the bag. Furthermore, the contents may be contaminated by the attack upon the adhesive binding the laminates, or on the metal foil.
There is thus need for a new bag construction, one that avoids the difficulties associated with known bags of the present type.